body {
    padding: 0;
    margin: 0;
}
.stageArea {
    width: 900px;
    min-height: 200px;
    margin-left: auto;
    margin-right: auto;
    padding: 100px 50px;
    background-color: #f0f0f0;
    box-shadow: inset 0 0 3px rgba(0, 0, 0, .35);
    perspective: 2000px;
    position: relative;
    top: 100px;
}
.container {
    width: 200px;
    height: 200px;
    position: absolute;
    left: 50%;
    margin-left: -100px;
    transform-style: preserve-3d;
    transition: transform 1s;
}
.imgItem {
    width: 200px;
    height: 200px;
    transition: opacity 1s, transform 1s;
    box-shadow: 0 1px 3px rgba(0, 0, 0, .5);
    position: absolute;
    bottom: 0;
}

#img1 {
    transform: translateZ(300px) rotateY(0deg);
}
#img2 {
    transform: translateZ(300px) rotateY(40deg); /* transform属性顺序十分重要 */
}
#img3 {
    transform: rotateY(80deg) translateZ(300px);
}
#img4 {
    transform: rotateY(120deg) translateZ(300px);
}
#img5 {
    transform: rotateY(160deg) translateZ(300px);
}
#img6 {
    transform: rotateY(200deg) translateZ(300px);
}
#img7 {
    transform: rotateY(240deg) translateZ(300px);
}
#img8 {
    transform: rotateY(280deg) translateZ(300px);
}
#img9 {
    transform: rotateY(320deg) translateZ(300px);
}